Fire engine



May 31, H WALKER FIRE ENGINE Filed April 2, 1930 n j J /7 Patented May 31, 1932 UNE-ree STA TESI HUBERT WALKER, or ELMIRA, NEW YORK, AssreNon 'ro AMERIOANLA FRANCE AND FOAMITE CORPORATION, AOORPORATION or iviiwvonr;`

FIRE ENGINE Application led Apri1'2, 1930. Serial No. 440,823.9.`

. The invention relates to automotive fire engines or pumpers, particularly those in which the propelling engine, which also operates'the pump, is water-cooled kor liquidcooled and its purpose is to compensate for the loss of cooling eiect which occurs when the engineis in operation driving thefire pump. The vehicle being stationary on such occasions, there is less air flowv through the engine radiator and overheatingon that ac,-

count is likely to occur. Theobject of the invention is'to utilize the temperature of the hydrant or pump water for providing addif,

tional cooling effect at such times but without diminishing lor affecting the fire-pump Output and without resort to large -or cumber-v some water passages -or chambers-for this purpose, thus,-in` a compact device, preserving the capacity of the pump quite the same as" though such additional cooling were not effected. To this end the invention involves the use of a heat exchanger connectedto the pump andV engine according to the principlesy hereinafter explained, and as exemplified in the accompanying ldrawings ,illustrating the form of the invention at present preferred. In said drawings, Fig. 1 is a side elevation of so much of an automotive fire engine as is necessary to understand the invention. Y

Fig. 2 an elevation partly in section and moreor less schematic in form, of the fire pump anditsconnections.

Fig. 3 a horizontal section on line III- III of Fig. 2.

Fig. :l a Section en une rv-iv of rig. 2, and Y Fig. 5 a modification. It will be understood that in motorized lire apparatus therek is a Vpropelling. engine, a

' transmission gear set 2 with'a shift lever 3, by

which the drive ratio of the engine to the propeller shaft4 and tractionwheels is controlled, and a power take-off represented by the gear casing 5 controlled by lever 6. This take-olf, when in use, causes the yengine to drive the fire pump 7 as will be understood from the drawings, and is used only when the vehicle is stationary, drawn 'up along side of a hydrant or other source of water. At such times the engine cooling is accomplished solely by the effect ofthe air YfanS drawing air through the radiatori), which is included, as usual, in the closed circulatingcooling system ofthe engine. The, engine cooling accomplished in this way, by fan only, is not or.y

dinarily suiiicientto keepthe engine from overheating, the vehicle being stationary and,r therefore deprived of the draft incident to the normal movement ofthe radiator through the atmosphere.

To avoid Y such overheating, various schemes have been' suggested, all of them however involving more or less restriction on the water iow through the fire pump and resulting in a less vigorous stream from the latter than if such extra cooling had not'been a flow of yhydrant water taken-from the fire line, preferably on the suction 'side of the pump. As will be apparent from the drawings the hydrant water passage is constituted by the header `boxes 10 connected witheach other through a series of multiple tubes 11; these boxes yhave drain cocksrlQ through either one of which the passages may be emptied of waterto avoid freezing and` they also have couplingor connection anges 13. for connection to the pump ,mechanismyas presently described. The other water passage is constituted by the spacewithin the casing 14 which surrounds the multiple tubes 11', which may be externally ribbed, if desired, and has its entrance on the top side marked 15 and its outlet on the forward side'marlred` 16. The top side entrance is ,connected through the pipe 17 with the base of the radiator 9 and the outlet 16 to the return pipe 18 leading to the engine water jackets lili) through the engine-driven circulating pump 19, which is usually present. Although referred to as a water circuit, it will be understood that within this term is included any liquid suitable for engine cooling purposes.

The fire pump 7 is mounted transversely on the vehicle chassis and may consist of kany suitable type of pump. Fig. 2 i11dicates it as a gear pump and Fig. 5 as a centrifugal pump, being there marked` 2l. In either case, it is provided with atleast two inlet connections 22, one preferably on each side of the vehicle and to which the supply hose from the hydrant is to be connected, as' indicated at 23. Normally only one of these connections is used at a time and the one not in use isf closed by its cap 24 and is termed the dead end of the pump. The pump also has two outlet or dischargeconnections 25, one on each sideof the vehicle to oneor both of which the lire hoses, such as 26, are to be connected. The pump may and generally does have other appurtenances not necessary to be shown in the present case.

The heat exchanger is mounted directly below and parallel tothe transversely disposed fire pump in which position the drain cocks 12 are easily accessible, and each of its coupling flanges 13 is connected by the curved drop pipes 27 to the two` opposed water inlets 22 of the pump, the drop pipesbeing long enough to locatethe heat exchanger just below the propeller shaft 4. In this arrangement a flow of hydrant Water is established through the heatv exchanger from its point of connection with the particular inlet connection 22, which happensl to be the dead end', to its o posite point of connection with the other in et 22, which is then connected by the hose 23 to the hydrant or water source, the flow being due tothe head established in the dead end by the effect ofthe water velocity created by the pump, the water rush- I ing toward such dead end in the direction of f the arrows and causing a reverseflow through the heat exchan er, also as indicated by the arrows. Such ow, due to velocityv headv in the fire line, occurs without adding any appreciable work on the pump and engine as will be a parent and it is assisted, more or less, by t e so-called thermo-syphonicr effect resulting from the fact that thehydrant water passingthrough the multiple tubes is warmed therein bythe heat' of the engine jacket water andconsequently.tends to rise into theiire line to be replaced by cool water therefrom. Such thermal: flow would take place even in the absence of any ow due to velocity head and will be seen therefore to be supplemental thereto and also to be the result, in part at least, of the location of the heat exchangerat a lower level than the pump. kFlow through kthe exchanger thus occurs from two causes, neither of which imposes any appreciable added burden on the pump and since use is made of the hydrant water on the suction side of the pump, such an exchanger can be compactly disposed on the vehicle without complicating the pump delivery mechanism and related parts, or in any way impeding access to the automotive engine or other mechanism. So far as the passage for the hydrant water is concerned, the action of the heat exchanger is reversible, that is to say, if the intake hose 23 were connected on the opposite side of the pump and the cap 24 on the opposite side from that shown, then the hydrant water ilow through the exchanger would be the reverse of that shown, but the cooling effect would be the same and it will be apparent from the drawings, the dimensions of which are substantially to scale, that the results referred to are accomplished with relatively small water passages, making an apparatus well suited by its compactness and lightness in weight to form a part of automotive fire equipment.

Its desirability for apparatus of this character, .where simplicity is so essential, is further enhanced by the fact that control valves are entirely unnecessary. The ends of the hydrant water passage being in free communication with the lire line at all times and connected therewith at points of different velocity head, the cooling flow through said passage is automatically initiated in response to operation oi' the pump and since the flow is proportional to the rate of pumping the engine 'temperature is eifectively controlled at all times and wit-hout requiring manual adjustment or valve manipulation, which not only take time when even seconds are val? able, but are likely to he overlooked.

lVhile Fig. 5 illustrates the application of the same principles to a centrifugal fire pump, as already stated, it will be apparent that the nature of the pump is immaterial, since in any case there will be a dead end where the velocity head will be available for creating flow of hydrant water rthrough the exchanger and the invention is in no respect limited to the style of pump employed, although the gear pump shown in Fig. 2 is preferred.

I claim:

l. T he combination with an automotive engine having a cooling-Water circuit and a power take-oil' for driving a fire pump, oit a heat exchanger comprising one water passage included in said coolingwater circuit and another adjacent water passage having its two ends connected to the iire line at points therein, on the same side of the vpump and between which there is a pressure difference due to the velocity head in said fire line.

2. The combination in a self-propelled fire engine, of the propelling engine connectible to the traction wheels and having a coolingwater circuit including a water pump, a power take-oilE for driving a fire pump, and a heatexchanger comprising one water pason the same side of the lire pump, one of said points of connection being subject to lvelocity head in saidfire line whereby water flow is established through said heat exchanger from said point of connectionto the other point. i

3.y The combination with an ,automotive engine having a cooling-water 'circuit and a power takeoif for driving a hre pump, of a heat exchanger comprising one water passage connected with said cooling water circuit and another water passage its ends connected to the iire line, on the same side of thev pump, and arranged to permit thermo-syphonicflow of water to said fire line by reason of the heat transferred from said cooling-water circuit. v

4. The combination with an automotive engine having a cooling water circuit and driving a pump, of a heat exchanger coniprising one water passageincluded in said circuit and another water passage having its ends connected with the pump-line and both on the same side of the pump, said exchanger being located at a lower level than the pump to promote thermo-syphonic flow through said other passage. y

5. The combination with an automotive power take-on' for driving a re pump, of a heat exchanger comprising one water passage another water passage connected to the fire line, at points on the saine side of the pump, one of which points is subject to a velocity head in said fire line Vsuited to establish .water flow from said point throughv said other passage to the other point, and said other passage being also arranged to permit thermo-syphonic water flow therethrough by the effect of heat received Y from said cooling 'water circuit,v whereby ed with said cooling water circuit and another water passage having both its ends connected to the suction side ofthe pump and receiving and conducting water by virtue of the velocity head at one of its said points of connection. y

7 In vapparatus of the kind described, an automotive engine driving -a pump having double opposed suction openings tofconstitute water inlets, a heat exchanger connected to and betweeen said inlets and means for transferring engine heat to said exchanger.

8. In apparatus ofthe kind described, an

having both engine having a coolingfwater `circuit and a connected with said cooling-water circuit andr having both its ends n exchanger having one water passage connect-y automotive Aengine adapted for. drivingl a pumpl and having av cooling-water circuit, a heat exchanger connected 'to said circuit and having/a water side of the pump ;v said exchanger being locatedfbelow said pump.

9.The combination with an automotive engine having a cooling-water circuit, a power take-off and a fire pump driven therebyfand provided with Aa water inlet anda dead end, of a heat exchanger havingrone water passageconnected with said circuit and. another water rpassage having its one end con# nected to the water inlet and its other end to the dead end. f v. 1

- 10. In a motor re pumper, the combination with an .automotive engine ,having a coolingTwater circuit and' connections for driving a re pump,

y passage connectedbetween points yof different pressure on the suction.

of a heat exchanger comprising one water passage included in said circuit and another water passage connected with thesuction side ofthe fire line, one pointy of vconnection being between the pump and the source of water and the other being be* yond thepump where the suction velocity establishes a pressure head.

o l1. In a motor fire offak propelling engine adapted for driving the traction wheels and having lapower takeoi', a fire pump transversely disposed on the vehicle having water inlets on opposite sides and avheatiexchanger also transversely dis-- posed'on the vehicle and below said pump and connected thereto, one part. of said exchanger vehicle, the combination i forming a passage for conducting pump kwater and another part being connected in cooling relation to the engine.

12. In an automotive lire pumper the combination of a propelling engine, a fire pump transversely disposed on the vehicle frame and adapted to be driven by said engine, water inlets for said pump extending on opposite sides therefrom and beyond the vehicle frame, a heat exchanger connected to said extended inlets and means for transferring engine heat to said exchanger.

13. f In automotive lire apparatus the com'-y bination of a propelling engine having a cool-- ing water circuit and adapted to drive a fire pump and having a power take-0E from its propeller shaft for such purpose, the combination of ay heat exchanger located in rear ofk the engine and adjacent said re pump and including two heat transferring water passages', one of which is connected in said cooling water circuit and the other of which is connected to the fire line to receive hydrant water therefrom. Y

14. In combination an automotive fire pumper having a propelling engine and a cooling-water circuit, a pump having intake and outlet connections to complete the iire line, a power take-off from the engine for driving the pump, a water pasfor attachment to hose f 4 1,seo,oas

sage arranged in parallel with'said re line with its ends in free communication therewith at all times, said ends connected to the j line at points of different velocity head to 5 promote water flow through said passage inV response to operation of the pump and a second Water passage constituting a part of said cooling-water circuit and arranged in heato exchanging relationship to said first pas- I sa The combination with an automotive engine having a cooling water circuit and a power take-olf for driving a fire pump, of a heat exchanger comprising an outer water u passage included in said cooling water circuit and an inner, adjacent Water passage having its two ends connected to the fire line at points therein on the same rside of the pump and between which there is a pressure differu ence due to the velocity head in said lire line.

16. In automotive fire apparatus', the combination of a water-jacketed engine having a continuous cooling water circuit and adapted to drive a fire pump, two Water passages lo# cated adjacent the pump and arranged in heat exchanging relation to each other, said continuous cooling Water circuit including the engine water jacket, a radiator, a connection t0 thetop of the same from said jacket,

a connection from the bottom of the radiator to one end of one of said passages and a connection from the other end of said passage back to the jacket, the other of said passages c. passingy pump water.

In testimony whereof I have signed this specification. y HUBERT WALKER. 

